Diet in mangrove snails: preliminary data on gut contents and stable isotope analysis

International audienc

Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system

<p>Abstract</p> <p>Background</p> <p>Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system.</p> <p>Methods</p> <p>A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: <b>x, y, z, and angle: θ, ϕ)</b>. Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state.</p> <p>Results</p> <p>Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min^-1vs. 10.53 min^-1) (p = 0.03).</p> <p>Conclusion</p> <p>MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.</p

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Cryptic Behaviour of Juvenile Turbot &lt;i&gt;Psetta maxima&lt;/i&gt; L. and European Flounder &lt;i&gt;Platichthys flesus&lt;/i&gt; L.

The aim of this study was to examine the burying behaviour of hatchery-reared European flounder Platichthys flesus and turbot Psetta maxima, and whether conditioning on a sandy substrate would improve burying efficiency. Both species buried shortly after release on a sandy substrate. However, the study revealed interspecies differences; the flounder buried immediately after release, while the turbot buried gradually. No significant difference in burying efficiency was observed between naïve and conditioned flounder and turbot. An effect of size on burial efficiency was observed for both flounder and turbot with a tendency for larger fish to bury more efficiently than smaller fish, despite previous conditioning. Size at settlement was found to be &gt;2 cm for flounder and &gt;3 cm for turbot

Turbulence along the shelf edge in the North Sea appears to generate heterogenity in plankton food web structure

Previous studies have demonstrated localised regions where mid-water column turbulence leads to elevated vertical nitrate flux at the shelf edge in the northeastern North Sea and predicted these fluxes to result in “patches” of enhanced new production in these regions. Here, we use data collected on the same cruise (July 2016) as these earlier studies to empirically test the hypothesis that this localised nutrient upwelling is reflected up the food web by first influencing phytoplankton community structure and production, which thereafter influences higher trophic levels in the plankton. Greater heterogeneity in plankton ecosystem structure was found in the shelf edge region compared to the rest of the study area. This was the only region where phytoplankton communities dominated by large cells were recorded and where the highest values for and greatest variability in Fv/Fm were found. Greater abundances of larger calanoids were also found here as well as the highest rates of Centropagus typicus egg production. We conclude that a signal from the localised nutrient upwelling previously recorded near the shelf edge cascades up the planktonic food web here